<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
/*
 * This is a PHP library that handles calling reCAPTCHA.
 *    - Documentation and latest version
 *          http://recaptcha.net/plugins/php/
 *    - Get a reCAPTCHA API Key
 *          http://recaptcha.net/api/getkey
 *    - Discussion group
 *          http://groups.google.com/group/recaptcha
 *
 * Copyright (c) 2007 reCAPTCHA -- http://recaptcha.net
 * AUTHORS:
 *   Mike Crawford
 *   Ben Maurer
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/**
* Recaptcha modified to integrate easily with Code Igniter
*
* @package     CodeIgniter
* @subpackage  Libraries
* @category    Captcha
* @author      Jon Trelfa <jtrelfa@gmail.com>
*/
class Recaptcha 
{
  
	var $_rConfig;
	var $_CI;
	var $_error;
	
	function __construct() 
	{
		$this->_CI =& get_instance();
		//$this->_CI->config->load('recaptcha');	//I'am loading from controller
		$this->_CI->lang->load('recaptcha');
		
		$this->_rConfig = $this->_CI->config->item('recaptcha');
		
		log_message('info',$this->_CI->lang->line('recaptcha_class_initialized'));
	}
	
	/**
	* Calls an HTTP POST function to verify if the user's guess was correct
	* @param string $privkey
	* @param string $remoteip
	* @param string $challenge
	* @param string $response
	* @param array $extra_params an array of extra variables to post to the server
	* @return ReCaptchaResponse
	*/
	function check_answer ($remoteip, $challenge, $response, $extra_params = array()) 
	{
		log_message('debug','Recaptcha::check_answer('.$remoteip.','.$challenge.','.$response.','.print_r($extra_params,TRUE).')');
		if ($this->_rConfig['private'] == '') 
		{
			log_message('error',$this->_CI->lang->line('recaptcha_no_private_key'));
			return FALSE;
		}
		
		if ($remoteip == null || $remoteip == '') 
		{
			log_message('error',$this->_CI->lang->line('recaptcha_no_remoteip'));
			return FALSE;
		}
	
		//discard spam submissions
		if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) 
		{
			$this->_error = 'incorrect-captcha-sol';
			return FALSE;
		}
		
		$response = $this->_http_post(
			$this->_rConfig['RECAPTCHA_VERIFY_SERVER'],
				"/recaptcha/api/verify",
				array (
					'privatekey' => $this->_rConfig['private'],
					'remoteip' => $remoteip,
					'challenge' => $challenge,
					'response' => $response
				) + $extra_params
		);
		log_message('debug','Recaptcha::_http_post response:'.print_r($response,TRUE));
		$answers = explode ("\n", $response[1]);
		
		if (trim($answers[0]) == 'true') 
		{
			return TRUE;
		} 
		else 
		{
			$this->_error = $answers[1];
			return FALSE;
		}
	}
	
	/**
	* Gets the challenge HTML (javascript and non-javascript version).
	* This is called from the browser, and the resulting reCAPTCHA HTML widget
	* is embedded within the HTML form it was called from.
	* @param string $pubkey A public key for reCAPTCHA
	* @param string $error The error given by reCAPTCHA (optional, default is null)
	* @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)
	
	* @return string - The HTML to be embedded in the user's form.
	*/
	function get_html ($lang = 'en',$use_ssl = false) 
	{
		log_message('debug','Recaptcha::get_html('.$use_ssl.')');
		if ($this->_rConfig['public'] == '') 
		{
			log_message('error',$this->_CI->lang->line('recaptcha_no_private_key'));
			return $this->_CI->lang->line('recaptcha_html_error');
		}
		
		if ($use_ssl) 
		{
			$server = $this->_rConfig['RECAPTCHA_API_SECURE_SERVER'];
		} 
		else 
		{
			$server = $this->_rConfig['RECAPTCHA_API_SERVER'];
		}
		
		$errorpart = '';
		if ($this->_error !== '') 
		{
			$errorpart = "&amp;error=" . $this->_error;
		}
		
		$str = '
			<script type="text/javascript">
			  var RecaptchaOptions = { 
				theme:"%s",
				lang:"%s"
			  };
			</script>
			<script type="text/javascript" src="%s/challenge?k=%s%s"></script>
			<noscript>
					<iframe src="%s/noscript?lang=%s&k=%s%s" height="300" width="500" frameborder="0"></iframe><br/>
					<textarea name="recaptcha_challenge_field" rows="3" cols="40"></textarea>
					<input type="hidden" name="recaptcha_response_field" value="manual_challenge"/>
			</noscript>
		';
		return sprintf($str, $this->_rConfig['theme'], $lang, $server, $this->_rConfig['public'], $errorpart, $server, $lang, $this->_rConfig['public'], $errorpart); 
	}
	
	/**
	* gets a URL where the user can sign up for reCAPTCHA. If your application
	* has a configuration page where you enter a key, you should provide a link
	* using this function.
	* @param string $domain The domain where the page is hosted
	* @param string $appname The name of your application
	*/
	function get_signup_url ($domain = null, $appname = null) 
	{
		return $this->_rConfig['RECAPTCHA_SIGNUP_URL'].'?'.$this->_qsencode(array ('domain' => $domain, 'app' => $appname));
	}
	
	
	/**
	* Encodes the given data into a query string format
	* @param $data - array of string elements to be encoded
	* @return string - encoded request
	*/
	function _qsencode($data) 
	{
		log_message('debug',"Recaptcha::_qsencode(\n".print_r($data,TRUE)."\n)");
		//http_build_query() = PHP 5 ONLY!
		return http_build_query($data);
	}
	
	/**
	* Submits an HTTP POST to a reCAPTCHA server
	* @param string $host
	* @param string $path
	* @param array $data
	* @param int port
	* @return array response
	*/
	function _http_post($host, $path, $data, $port = 80) 
	{
		log_message('debug','Recaptcha::http_post('.$host.','.$path.','.print_r($data,TRUE).','.$port.')');
		
		$req = $this->_qsencode($data);
		$http_request = implode('',array(
							"POST $path HTTP/1.0\r\n",
							"Host: $host\r\n",
							"Content-Type: application/x-www-form-urlencoded;\r\n",
							"Content-Length:".strlen($req)."\r\n",
							"User-Agent: reCAPTCHA/PHP\r\n",
							"\r\n",
							$req));
		$response = '';
		if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) 
		{
			log_message('error',$this->_CI->lang->line('recaptcha_socket_fail'));
		}
		
		fwrite($fs, $http_request);
		while (!feof($fs)) 
		{
			$response .= fgets($fs, 1160); // One TCP-IP packet
		}
		fclose($fs);
		$response = explode("\r\n\r\n", $response, 2);
		
		return $response;
	}
}
